<template>
  <div class="upload-container">
    <el-upload
      :data="dataObj"
      :multiple="false"
      :show-file-list="false"
      :on-success="handleImageSuccess"
      class="image-uploader"
      drag
      action="https://httpbin.org/post">
      <i class="el-icon-upload"/>
      <div class="el-upload__text">将文件拖到此处，或<em>点击上传</em></div>
    </el-upload>
    <div class="image-preview">
      <div 
        v-show="imageUrl.length>1" 
        class="image-preview-wrapper">
        <img :src="imageUrl+'?imageView2/1/w/200/h/200'">
        <div class="image-preview-action">
          <i 
            class="el-icon-delete" 
            @click="rmImage"/>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
// 预览效果见付费文章
import { getToken } from '@/api/qiniu';

export default {
    name: 'SingleImageUpload',
    props: {
        value: {
            type: String,
            default: ''
        }
    },
    data() {
        return {
            tempUrl: '',
            dataObj: { token: '', key: '' }
        };
    },
    computed: {
        imageUrl() {
            return this.value;
        }
    },
    methods: {
        rmImage() {
            this.emitInput('');
        },
        emitInput(val) {
            this.$emit('input', val);
        },
        handleImageSuccess() {
            this.emitInput(this.tempUrl);
        },
        beforeUpload() {
            const _self = this;
            return new Promise((resolve, reject) => {
                getToken().then(response => {
                    const key = response.data.qiniu_key;
                    const token = response.data.qiniu_token;
                    _self._data.dataObj.token = token;
                    _self._data.dataObj.key = key;
                    this.tempUrl = response.data.qiniu_url;
                    resolve(true);
                }).catch(err => {
                    console.log(err);
                    reject(false);
                });
            });
        }
    }
};
</script>

<style rel="stylesheet/scss" lang="scss" scoped>
    @import "src/styles/mixin.scss";
    .upload-container {
        width: 100%;
        position: relative;
        @include clearfix;
        .image-uploader {
            width: 60%;
            float: left;
        }
        .image-preview {
            width: 200px;
            height: 200px;
            position: relative;
            border: 1px dashed #d9d9d9;
            float: left;
            margin-left: 50px;
            .image-preview-wrapper {
                position: relative;
                width: 100%;
                height: 100%;
                img {
                    width: 100%;
                    height: 100%;
                }
            }
            .image-preview-action {
                position: absolute;
                width: 100%;
                height: 100%;
                left: 0;
                top: 0;
                cursor: default;
                text-align: center;
                color: #fff;
                opacity: 0;
                font-size: 20px;
                background-color: rgba(0, 0, 0, .5);
                transition: opacity .3s;
                cursor: pointer;
                text-align: center;
                line-height: 200px;
                .el-icon-delete {
                    font-size: 36px;
                }
            }
            &:hover {
                .image-preview-action {
                    opacity: 1;
                }
            }
        }
    }

</style>
